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Powerful(1) numbers (A001694) whose digit reversal is a semiprime (A001358).
2

%I #5 Mar 30 2012 17:40:35

%S 4,9,49,64,121,169,289,400,512,625,900,961,968,1156,1225,1568,1849,

%T 2048,2401,2888,3125,3136,3364,3481,3721,4000,4900,4913,5041,5329,

%U 5408,6400,6859,6889,7396,8192,8575,9000,9604,10201,10648,10816,10952

%N Powerful(1) numbers (A001694) whose digit reversal is a semiprime (A001358).

%H <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a>

%e 968=2^3*11^2 is powerful and 869=11*79 is semiprime.

%Y Cf. A001358, A001694, A115688.

%K nonn,base

%O 1,1

%A _Giovanni Resta_, Jan 31 2006